var map = new WeakMap()
var innerObj = {}
class Article {

	set data(data) {
		console.log('set..',data)
	}
	get data() {
		console.log('set....')
		
		if(!map.has(this)) {
			map.set(this, innerObj)
			return innerObj
		}

		return map.get(this) 
	}
}


var a = new Article();
console.log(a)

// a.data = 'hello'
a.data['aa'] = 'hello aa'
console.log(map)
console.log(innerObj)
console.log(map.get(a))
console.log(map.get(a).aa)


